The fluted aluminum seatpost on my Redline Squareback has been in the frame since the 1970's. The guy I got it from left the bike on the side of his house for the past 20+ years. It's a fluted post so there's room to get fluids in the seat tube. I've had some luck with Kroil in the past, soaking it for a few days but not this time, this one is froze tight. Put a propane torch on the seat tube as that's not as hot as acetylene so it doesn't harm the finish but no luck. Also tried an impact hammer pulling it upward. Won't budge.

I don't want to ruin the nickel finish with acetylene so I'm asking if anyone has any ideas OTHER THAN a machine shop boring it out. Ideas anyone?

Still searching for my missing bikes from BITD. 1979 Blue Max serial: CI9 221346 and 1977 Webco serial: 42667. Both were last seen at Spoke and Sport Bicycles in Spokane, WA around 1984. $600 reward if found!!

"Have you ever noticed that other people`s stuff is shit and your shit is stuff?" - George Carlin

- take the cranks and bottom bracket out of the frame - put the frame upside down - pour about 1/2 cup ammonia into seat tube thru the hole where the eat tube meets up with the bottom bracket shell. - let it sit for a week. - try to remove the stem.

If it doesn't come out, use some more thermal cycling to try to loosen it up:

- put a bowl of ice water (mostly ice) on the floor with the frame upside down in it, so the seat post is mostly in the bowl - let it sit for an hour or so - try removing the post - take it out of the water and use a hair dryer or heat gun to warm the seat tube and post up. try removing again - repeat the ice bath / heat gun steps 2-3 times

Use a hacksaw blade to cut a vertical slot into the post. Carefully cut it almost all the way through without damaging the seat tube. Once there is a big enough slot, clamp it in a vise and turn it out.

From my experience, take it to a machine shop. Unless one of these tips works for you. The aluminum corrodes (thus expanding the post size) and bonds with the steel. I suffered through this once. Got past the point of no return (meaning I'd destroyed any bit of a useable post by clamping, drilling, slotting, etc) and literally took out the post in a thousand pieces.

SoGnarly wrote:

blackflag wrote:

Much thanks. Unfortunately, '74/'75 Squares don't have a hole at the seat tube/bottom bracket juncture. At least mine doesn't anyways. I like the idea for sure though.

Fill the seat tube up with WD or something like that, bring it inside and let it sit a while. Heat on the seat tube, not alu post, should work.

I already soaked it in Kroil. At $20 per can, Kroil is 10 times the penetrating oil that WD is. I filled the seat tube and let it sit for three days Also as I said, put a propane torch on it.. If Kroil couldn't loosen it, WD-40 definitely won't. I'm gonna try vinegar, then the acid bath and see if there's a chance that either of those might do it. Machine shop is the LAST resort.

ace inc wrote:

Use a hacksaw blade to cut a vertical slot into the post. Carefully cut it almost all the way through without damaging the seat tube. Once there is a big enough slot, clamp it in a vise and turn it out.

I don't understand what the vertical slot is for. I can clamp it in a vise right now and twisting it out was the first thing I tried. The frame was flexing too much so I felt like I had to back off. Please elaborate on the Vertical slot?

Dissolve the aluminum seat post with Lye (sodium hydroxide). Takes time but people say it works. I've used Greased Lightning which contains Sodium Hydroxide to quickly remove anodizing.

There's another lubricant that people have been using to remove stuck/frozen items. It is made by CRC and called Freeze Off. Costs about $6-7 a can from the local auto parts store. I've personally used it on frozen bolts. Way faster than Kroil or PB Blaster.

skaman wrote:

Dissolve the aluminum seat post with Lye (sodium hydroxide). Takes time but people say it works. I've used Greased Lightning which contains Sodium Hydroxide to quickly remove anodizing.

There's another lubricant that people have been using to remove stuck/frozen items. It is made by CRC and called Freeze Off. Costs about $6-7 a can from the local auto parts store. I've personally used it on frozen bolts. Way faster than Kroil or PB Blaster.

So the lye won't hurt chromoly or nickle plating but it'll completely dissolve aluminum? How much time are you thinking it'll take?

blackflag wrote:

So the lye won't hurt chromoly or nickle plating but it'll completely dissolve aluminum? How much time are you thinking it'll take?

Thanks for the tips!

I've never done it so no first hand experience. What I've read about it is that the time depends on the concentration of Sodium Hydroxide. I read one account where it took a day to dissolve a aluminum seat post but if you decide to go this route, then it best to check it periodically.

I discovered the hard way (almost disintegrated my Shimano DX pedals ) that the Drano crystals will dissolve aluminum very fast. It also bubbles and heats up like crazy. I dont know if it will effect the nickel plating so if you use this method do so with caution so as not to spill it on the finish. Mix some crystals in water and carefully pour into the seatpost. Dont fill too much because it does bubble. Seatpost will dissolve enough for you to be able to get it out.

blackflag wrote:

ace inc wrote:

Use a hacksaw blade to cut a vertical slot into the post. Carefully cut it almost all the way through without damaging the seat tube. Once there is a big enough slot, clamp it in a vise and turn it out.

I don't understand what the vertical slot is for. I can clamp it in a vise right now and twisting it out was the first thing I tried. The frame was flexing too much so I felt like I had to back off. Please elaborate on the Vertical slot?

Insert the hacksaw blade right into the seatpost and cut the length of it (up and down). If the blade wont fit down the post, you can try a small round file.

Keep sawing or filing until you have cut a channel along the whole length of the post.

It's slow going, but I managed to remove a frozen aluminum seatpost that had broken off flush with the top of a chromoly frame.

My recent experience....had a Uni post stuck in a TNT. 1 or 2 days of PB Blaster (which I'm not sure did anything), then clamped an old broken stem to the post, then 2# maul to the stem. Took a ton of pounding, and eventually began to move in 1/16" increments. Finally it popped out. I couldn't imagine dissolving an aluminum seat post. You're gonna have a chemical plant in your garage or whatever.

Since it is fluted, it would also be much easier to drill out. Also, much easier to do the above hacksaw trick.

Hutch Fun Facts: All main line Hutch's with digits only S/N (no letters or baseballs) on the rear drop outs were US made and had their dropouts stamped between late '83 and '86. Obviously the frame manufacture would occur slightly after that, even if they just threw 'em in a bucket randomly. There is an obvious date code in that the first 2 digits seem to be the month and the 3rd digit is pretty obviously the last digit of the year running from '83-'86.

See, now the stem won't let go of the post....Okay, I never bothered to separate them.

Hutch Fun Facts: All main line Hutch's with digits only S/N (no letters or baseballs) on the rear drop outs were US made and had their dropouts stamped between late '83 and '86. Obviously the frame manufacture would occur slightly after that, even if they just threw 'em in a bucket randomly. There is an obvious date code in that the first 2 digits seem to be the month and the 3rd digit is pretty obviously the last digit of the year running from '83-'86.

XJguy wrote:

What you have going on there is galvanic action, the two are fused.

I discovered the hard way (almost disintegrated my Shimano DX pedals ) that the Drano crystals will dissolve aluminum very fast. It also bubbles and heats up like crazy. I dont know if it will effect the nickel plating so if you use this method do so with caution so as not to spill it on the finish. Mix some crystals in water and carefully pour into the seatpost. Dont fill too much because it does bubble. Seatpost will dissolve enough for you to be able to get it out.

Use protective goggles.

Do not forget that vertilation is equally important.

Lye wont harm the ferrous steel, but the heat reaction could be potentially a problem and nickel is a transitional metal ... Look to see if drano harms nickel on the interwebz

do what troynlori did, put 2 towels on each side of the seat post mast and cushion the frame. Get an air hammer and pound on that stem. It will take about 7-10 mins of bam bam bam bam bam bam - your arm will definately get tired. It will come out - no doubt.I used a rivet gun with a flat top on it.

WOW!!!! there is a set i have it is a pipe extractor set. the best money i ever spent. works great !really you must own this or know where to get one. i think you can rent the set from your local auto parts store. make life sooo much easier. trust me guys check in to it. ive pulled 3 very very very stuck seat post out with it. 80' motomag 83' predator. the worst of all was a fluted seatpost in a 83' DB silver streak. that i found at my local scrap yard. it had been there a long time.then if that does not work machine shop tell them you want it line board out. also TRI-FLOW the answer to everything

I wish tri-flow was the answer to everything. I had a good run when it came to stuck seat posts but have recently come across two in a row. The last was fluted and tri-flow did the job. The current is completely frozen and tri-flow did nothing. It's aluminum and frozen in a steel frame(proper post for the frame and not driven in to far), I believe I've tried all related steps on the sheldon brown page(plus an OA bath) so now it's time for caustic soda. Has anyone actually gone this route; using sodium hydroxide to dissolve the post? Any tips/advice/lessons-learned from your experience would be appreciated. Also, anyone know where or if you can purchase small amounts of caustic soda as opposed to having to buy an 8lb bag of lye? I'll document my experience with pix in this thread if I do go this route, at this point I don't see any other options.

'With your chrome heart shining in the sun, long may you run'

"Do you have any idea what the street value of this mountain is?" -Charles De Mar